YAOUNDE (Reuters) - An improvised bomb wounded three policemen in the main city of Cameroon’s minority English-speaking region on Thursday, the regional governor said, in an attack a senior security source blamed on separatist militants.

Speaking on state TV, Adolphe Lele Lafrique, Governor of the North West Region, referred to a “terrorist attack” in the city of Bamenda, in the western part of the country.

A senior security source told Reuters by telephone the attack was the work of “extremists” who want independence for the Anglophone part of mostly French-speaking Cameroon.

If true, it would represent a dangerous escalation of a conflict that had thus far pitted only unarmed demonstrators against the security forces. The security source said the separatists had also launched other attacks in the past three weeks, including burning down several schools.

“Today, police working in the service of the nation were targeted in a terrorist attack,” Lafrique said. “This is a new stage in the situation we have been dealing with up until now.”

Cameroonians in the English-speaking west of the country have over the past year sporadically protested against what they describe as discrimination by the overwhelmingly Francophone government of President Paul Biya.

A small minority want an independent state, which they call “Ambazonia”. They have their own flag and a banned TV station, but none had yet been implicated in militant attacks.

In response to protests, security forces last year shot dead six protesters, arrested hundreds and charged their leaders with crimes, some of which carry the death penalty. Authorities also unplugged the region’s internet for three months.

Biya this month ordered a military court to drop its prosecution against several of the detainees, but his apparent gesture of reconciliation did little to calm tensions. Days later, Anglophone Cameroonians boarded up their shops, stayed home from work and boycotted the start of the school term.

The linguistic division harks back to the end of World War One, when the League of Nations divided the former German colony of Kamerun, in central Africa, between allied victors, leaving most of Cameroon French-administered but a small part run by Britain.